Conventional vehicle roof systems generally include a roof panel and a headliner forming a ceiling of the vehicle. Roof panels may include elongated beads to provide increased structural strength. Headliners may include layers of materials such as a foam layer covered with a cloth material. As one example, a headliner may include an inner decorative layer to provide a pleasing visual appearance. In addition, the headliner may include a layer which is intended to absorb sound to reduce noise.
Current roof panels tend to be relatively thick and heavy to meet various structural requirements. Accordingly, a need exists for roof panels that include strengthening features so that thicknesses of the roof panels can be reduced.